Pin Me

Windows Firewall - To Block or Unblock - The How and Why of Allow and Deny

written by: •edited by: Lamar Stonecypher•updated: 11/12/2008

A firewall like the one built into Windows is only useful if you use it correctly, and this article will help you to understand what programs you should allow or deny your network connection.

  • slide 1 of 1

    Allow or Deny?

    Your home computer should have some kind of firewall running, especially if you are on a DSL or cable modem connection. There are plenty of free and commercial firewall programs available online, but Windows XP and Vista also have one built in. To turn it on, just go to the Control Panel, then Windows Firewall and check the settings.

    Once your Windows Firewall is active, you may occasionally get a pop-up window asking you to Unblock or Keep Blocking an application. Sometimes the application in question is something familiar, such as iTunes or Microsoft Outlook, but sometimes you don’t even know what the program is that’s trying to access the internet. This article will help you to differentiate between threats and legitimate programs.

    When your firewall questions you about allowing a program access to the internet or network connection, the first thing you need to ask yourself is why that program wants access. If it is a web browser or any other kind of software that connects to the Internet, then it should be a no-brainer. You can’t browse the web in Firefox if you don’t allow Firefox to access the Internet connection, right? The same goes for Outlook or iTunes.

    There are really only three main reasons why a program would want to connect online when you open it:

    1. Because it is an Internet program, such as a browser or email software. Another good example is a computer game that allows you to play online.
    2. Because it is checking for updates, such as how a virus scanner updates itself constantly.
    3. Because it is validating a serial number or registration information. Very few programs need to do this, though.

    What you really have to watch out for are ‘free’ programs that aren’t really free. For example, you download a game from some website, then when you want to play it the Firewall pops up asking you to allow or deny some program you’ve never heard of, or a program whose name sounds nothing like the game you downloaded. Chances are it is some kind of adware that came piggybacked on the game installation. You have to be especially careful of any online fire sharing programs, as the majority of them also include adware.

    If in doubt, it is best to Keep Blocking that program. If you later realize that this is preventing something you need from working, just go back into the Windows Firewall settings and uncheck the box next to that program under the Exceptions tab. I also like to search the name of program executable (*.exe file) in Google to help identify them. Often times those weird program names are just system files and are not a threat, but it never hurts to make sure.

    Just having a firewall running on your computer is not the end-all of computer security. It’s a tool to help protect your computer, but it still takes some common sense on your part. For example, having a firewall running is not going to stop you from getting a virus from an email attachment, because you’ve already authorized your email program to access the Internet. Furthermore, a firewall is not a virus scanner and will not even know how to detect one, nor will it detect malware. All a firewall will do is allow or deny incoming and outgoing connections from individual programs. It’s up to you to know which programs need access and which ones don’t.